1. Field of the Invention
The present invention relates to image processing. More particularly, the present invention relates to a method and apparatus for scalable image processing employing multiple graphics functional units.
2. Background
Computer graphics technology has advanced at a rapid pace in recent years. As each new computer graphics system is introduced, competitive forces and the desire to improve upon prior systems have resulted in graphics functional units with graphics feature sets more complex than the ones they replaced. Advanced features in many current graphics functional units include video overlay, scaling, panel fitting in VGA modes, 3-D graphics and support for 32-bits-per-pixel (BPP). While the enhanced feature sets greatly improve graphics processing capability, the additional logic increases power requirements. The additional logic also generates more heat, thus requiring more advanced heat dissipation systems.
Although many of the advanced features included in modern graphics functional units are either required for, or enhance the performance of modern application programs, most “Business graphics” applications require graphics functional units that have a relatively small graphics feature set. Business graphics applications typically include email, spreadsheet and word processing applications.
An improvement in the scalability of image processing is made possible using multiple graphics functional units. In such a system, the graphics functional unit that the user wants to use is selected by operating a switch. Alternatively, the graphics functional unit may be selected via an input device that the user operates to execute a setup program or the like after the system has been turned on.
Some conventional computer systems allow an optional graphics functional unit to be connected, in addition to the built-in graphics functional unit, in a manner such that the optional graphics functional unit is located either inside or outside the main body of the computer system. Even if an optional graphics functional unit is located within the main body, the built-in controller is typically selected prior to the optional graphics functional unit Moreover, the graphics functional unit may typically be changed only during initialization. These approaches typically require rebooting the computer whenever a graphics functional unit is changed.
The above approaches are poorly suited for many uses. Many computer users infrequently execute applications requiring advanced graphics features. Other computer users may switch between applications requiring a variety of graphics features within a short amount of time. Rebooting a computer in order to switch a graphics functional unit is unacceptably burdensome for the computer user.
Accordingly, a need exists in the prior art for a method and apparatus for scalable image processing that reduces power consumption and increases battery life when a graphics functional unit system is operated in business graphics mode. In addition, a need exists to provide such a system that adaptively changes graphics modes according to current operating conditions.